The present invention relates generally to a chucking spindle arrangement for use in a thread winding device where threads, yarns, filaments or the like are wound onto a bobbin carrier or core sleeve. In particular, the present invention relates to an improved chucking spindle which forms a part of the winding shaft on such a device and which is expandable in order to secure the bobbin carrier thereto.
A number of different chucking spindle constructions are known for securely locking bobbin carriers onto the carrying arm or winding shaft of thread winding machines. For example, so-called bar tension chucks have a wide enlargement or an axially slidable cone mounted on the chucking shaft which cooperates with respect to a counter-cone arrangement. In securing the bobbin carrier to the chucking device, the counter-cone is moved radially outward by shifting the axially slidable cone thereby gripping the bobbin carrier thereabout.
However, such cone-type chucking spindles have the disadvantage that a slide fit is required between the chuck shaft and the cone. This slide fit is of a very complicated design since otherwise, after a relatively short operational period, jamming and rusting inside the slide fit would occur, thereby taking the entire chucking spindle out of operation.
In order to overcome these drawbacks found with cone-type chucking spindles, clamping elements that operate according to the so-called "freewheeling" or coasting principle were developed. An example of such a chucking spindle is disclosed in U.S. Pat. No. 3,815,836 to Munnekehoff et al. Such chucking spindles are especially advantageous in that the clamping elements thereof are self-locking so that even with the introduction of high torsional or braking forces the bobbins will remain securely clamped.
However, in spite of the mechanical advantages of such "freewheeling" chucking spindles, several operational difficulties have been encountered in their use. Since the mounting and removal of the bobbin carriers takes place by means of turning them by hand in order to disengage the clamping elements of the device while simultaneously moving the carriers axially on or off of the chucking shaft, if several bobbin carriers are arranged in axial succession on a single chucking spindle, the rearmost bobbin carrier must be slid over all of the front clamping zones in order to mount or remove it. Hence, with great care the bobbin carrier must be constantly rotated by hand from the front to back of the chuck shaft as it is slid thereon and this process must be again repeated when it is removed.
The chucking spindle of the present invention was developed in part to take advantage of the desirable self-locking features of the known "freewheeling" spindles, while at the same time avoiding all of the above-described disadvantages of conventional chucking spindles. The present invention also led to a number of special clamping elements which can be automatically disengaged or released from the bobbin carriers.